Recorder



Sept. 13, 1938.

HARRISON RECORDER Filed Jan. 31, 1934 9 Sheets-Sheet l s s Q ATTORNEYSept; 3,1938. L. s. HARRISON 2,129,762

RECORDER Filed Jan. 31, 1934 9 Sheets-Sheet 2 ATTORN EY Sept. 13, 1938.

| s. HARRISON.

RECORDER Filed Jan. 31, 1934 O 75 lll ul 9 Sheets-Sheet 3 INVENTORATTORNEY p -'13, 193s. j L. s. HARRISON 2, 9

RECORDER Filed Jan; 51, 1934 9 Sheets-Sheet 4 INVENTOR- ATlfORNEY- Sept.13, 1938'.

L. S. HARRISON RECORDER Filed Jan, I 51, 19:54

l I 'I- L. .J'IL J P- I '80 r 7 66m 66m 56111 9 Sheets-Sheet 6 \WIHMINVENTOR 0%??? MM I ATTORNEY s p 13, 1938- L.- s. HARRISON 2,129,762

RECORDER Filed J an. 31, 1934 9 Sheets-Sheet 7' INVENTORI ATTORN EYSept. 13, 1938. 5 HARRISON v 7 2,129,762

RECORDER Filed-Jan. 31, 1934 9 Sheets-Sheet a RG19. 18l- 242 '8INVENTOR- BY M ATTORNEY- Patented Sept. 13, 1938 RECORDER Laurence S.Harrison, Binghamton, N. Y., assignor to International Business MachinesCorporation, New York, N. Y., a corporation of New York ApplicationJanuary 31, 1934, Serial No. 709,138

20 Claims.

This invention relates to recorders in general, particularly the typeusing a chart.

The broad object of the invention is to provide a noval recordersuitable for recording transient phenomena of various kinds, such as theopening and closing of doors; the operation of circuit breakers, oilswitches, generators, andother electrical apparatus and machines; theoperation of machinery of all kinds, for instance, batteries of papermaking machines, wire forming machines, rolling mills, and the like;and, in general, processing machines and apparatus of all kinds.

.In brief, the broad object is to provide a recorder of the strip charttype which is capable of general use and adaptable to a large number ofconditions where an accurate and reliable recorder is necessary.

Heretofore, it has been customary to feed the charts of recorders usingstrip charts at a constant speed so that distances measured along thelength of the strip represent coordinates of time. In other words, thechart is constantly in motion. This type of construction is satisfactoryand very essential in recording voltmeters, ammeters, Wattmeters,thermometers, pyrometers, and the like Where conditions are constantlychanging but is not desirable in recorders for transient phenomena suchas overloads, short circuits, and occasional severe line disturbances ofY electrical power systems; the starting and stopping of processingmachines or apparatus of different kinds; locking or unlocking of doorsand closing or opening of water or fireproof -bulkheads, and a multitudeof other operations which may take place at infrequent intervals of timeor, at best, with a considerable lapse of time between successivelyoccurring phenomena.

The main reason for the undesirability of a constant paper feed inrecording transient phenomena like those outlined above is the largewaste of chart paper which usually results. As an illustration, take acircuit breakerrecorder using a strip chart, several forms of which havebeen developed. When these recorders are used in connection withelectrical transmission systems and networks, it is usually true that,once the system or network has been started in full operation, andexcept for a few routine operations of circuit breakers and oil switchesat prearranged times, changes in the status of the circuit breakers andoil switches occur only at very infrequent intervals of time and arecaused mainly by transient line disturbances, short circuits, andunexpected overloads. This means that the chart paper may be fed forhours before any significant change in line or system conditions, makeschanges in the status of the system apparatus necessary. The actualamount of waste of chart is very difficult to determine accurately, butit is easily possible for wastage amounting to from to to occur. As thespecially ruled charts are very expensive, the

waste of this paper may amount to a considerable expense particularlywhen a large number of recorders are necessary.

Another undesirable feature of the constant feed of the chart is thelarge amount of space required for storage of the rolls of used chartswhich, for reasons obvious to those skilled in the art, must bepreserved intact even when only a few parts of a roll are of interest.As the charts must, in a majority of cases, be kept for some time beforebeing destroyed, the space required for their storage may be quitelarge.

One of the objects of the invention, therefore, is to provide a recorderfor transient phenomena wherein the chart is fed a predetermined lengthat a constant rate of speed only when the phenomena to be recordedoccurs.

Another object is to provide a recorder wherein the exact time isprinted at least once on each predetermined length of chart fed in orderto provide a convenient time reference point for determining the exacttime of occurrence of all phenomena which may occur during the intervalof time while the chart is being fed a predetermined distance.

A disadvantage of graphic recorders of present types is the diflicultyof accurately determining the exact time when a change in conditions(such as voltage, current, temperature, or the like) occurs due to thefact that the chart is usually fed so slowly that measurements made witha scale cannot be expected to be much more accurate than to within aquarter of a minute of the correct time and to get such accuracy thechart must be fed fairly fast, say five or six inches per hour. As anexample, one type of circuit breaker recorder has its chart fedconstantly at the rate of three inches per hour. Obviously, it is notpractical to rule a chart for such a recorder with lines closer thanabout $4 in which case the lines would be 30 seconds apart. An accuracywithin one quarter of a minute but not much greater can be had from sucha chart but there is a great waste of chart. If the chart feed isreduced for economy of chart the accuracy of measurements is greatlyreduced while if the feed is increased to secure greater accuracy, acorresponding increase in waste results.

Accordingly, one of the objects of the present invention is to provide arecorder wherein the chart is normally at rest and is fed an appreciableamount at a constant rate in a short space of time only on theoccurrence and under control of transient phenomena. At some point inthis predetermined feed the exact time, say in hours and minutes, isstamped upon the chart thus enabling the exact time of phenomena. to bereadily ascertained by measurement.

The feed is of sufficient length and of long enough duration to enablethe time of all phenomena occurring during the feed of the chart to beaccurately determined either by means of suitable lines ruled on thechart or by a properly graduated rule. Great accuracy may thus besecured but at the same time economy of chart is secured. Any reasonablenumber of entries can be made on the predetermined length of chart andtheir time relation to each other accurately determined to within onesecond or even less by reference to the exact time stamped on the chart.

A further object is to provide means for recording on each predeterminedlength of chart a plurality of transient phenomena which may occurduring the time the chart is being fed a predetermined length.

Another object is to provide means to automatically print adjacent thefirst recordal of transient phenomena on each predetermined length ofchart a suitable special character, such as an arrow, for identifyingthe first recordal.

Still another object is to provide a chart feeding mechanism which isdriven by a motor that is in operation and using current only during theintervals when the chart is being fed predetermined lengths.

There is another important disadvantage of former types of recorderswhich the present invention eliminates. The charts of former recordershave been fed almost invariably by means of spring-driven clocks and insome cases, it is believed, by alternating current motors of thewellknown synchronous type now commonly used in electric clocks andtiming devices of various kinds. When spring-driven clock movements areused, various difficulties may be experienced, one of the most annoyingof which difllculties is poor time keeping characteristics of thespringdrive movements used for this purpose.

The heavy load placed on the clock movement by the chart drive mechanismaffects the accuracy of the movement to some extent, as does thetemperature of the switchboard room which may be quite high due to thepresence of various kinds of heat producing apparatus. The necessity forcompactness, combined with the requirement of sufficient power to feedthe chart, make it difiicult to construct a clock movement which is bothcheap, accurate, and reliable. Obviously, the clock movements inrecorders of the strip chart type must be very well constructed andcarefully inspected and adjusted at frequentintervals to insure constantaccuracy. Furthermore, attendants sometimes forget to wind the movementor wind it too tight and troubles result from both acts of carelessness.

The use of an alternating current synchronous motor clock movement inplace of a spring driven clock movement results in compactness and fairtime keeping properties as long as the load on the motor is constant butthe accuracy of the motor driven movement is likely to be affected tosome extent by variation in the load due to the gradual increase in sizeof the chart storage roll as the chart supply roll unwinds, particularlywhen friction tapes or belt devices are used to keep the chart taut, asis usually the case. Furthermore, an interruption in the supply ofalternating current to the synchronous motor naturally will render therecorder useless.

Accordingly, an object is to provide a compact driving and timingmechanism for recorders which mechanism is very accurate, reliable,simple in construction, requires little adjustment or repair, and iscapable of operation independently of the alternating current supply inan emergency.

Another object is to provide a novel control switch for attachment toeach machine, device, or apparatus whose operations are'to be recorded.

An object is to provide simple and efficient inking ribbon feedingmechanism suitable for recorders.

A further object is to provide a novel arrangement whereby the recorderis automatically operated each time the cabinet or case enclosing therecorder is removed for inspection, repair, replacement of the chart, orremoval of a length of the chart, as at the end of a day, week, or monthand the recorder is automatically operated when the case is replaced.

Another object is to provide means whereby the records made when thecabinet or casing is removed are in a color contrasting with the recordsmade when the recorder is operating in the normal way.

Various other objects, advantages, and features of the invention will bementioned in the following description and claims or will be apparentafter a study of description, claims and drawings.

In the drawings:

Fig. 1 is a front elevation of the recorder with the enclosing caseshown in section.

Fig. 2 is a vertical section on the line 2-4 in Fig. 1.

Fig. 3 is a vertical section on line 3-3 in Fig. 1.

Fig. 4 is a vertical section on line 4l in Fig. 1.

Fig. 5 is a view of two fragments of the chart.

Fig. 6 is a perspective view of certain of the printing elements.

Fig. '7 is a circuit diagram.

Fig. 8 is a large scale view in elevation of one of the arrow printingdevices.

Fig. 9 is a vertical section on line 9-9 in Fig. 19.

Fig. 10 is an end view of one of the frames carrying the interposermagnets.

Fig. 11 is a vertical section on line H--H in Fig. 1.

Fig. 12 is a large scale side elevation of the synchronous motor and itsconnections.

Fig. 13 is a large scale front view of the synchronous motor.

Fig. 14 is a large scale side elevation of the driving clutch for thechart feed mechanism and certain associated parts and shows the parts innormal position.

Fig. 15 is a view similar to Fig. 14 but shows the clutch and relatedparts in operated position.

Fig. 16 is a large scale detail view of the assembly including theclutch dog and contact trip dog.

Fig; 17 is a vertical section in the line ll-H in Fig. 14.

Fig. 18 is a vertical longitudinal section on the line I8-|O in Fig. 19and illustrates the construction of one of the control switches whichmay be attached to a device whose operations are to be recorded.

Fig. 19 is a transverse vertical section of the control switch shown inFig. 18.

Fig. 20 is a large scale rear elevation of the mechanism forautomatically feeding the inking ribbon.

Fig. 21 is a large scale front elevation of the mechanism for feedingthe inking ribbon.

Figs. 1 to 4 are a series of general views showing the parts of therecorder in their normal positions. The recorder is shown in these viewsas having a rectangular mounting plate 30 by means of which the recordermay be secured to a wall or a switchboard panel. A suitable dust proofcabinet or case 3!, removably attached to the plate 30, encloses theworking parts and has one or more glass panels 32 which permit visualinspection of the chart 33 and the working parts of the recorder withoutremoving the case 3 I.

Mounted on the plate 30 are two parallel frame plates 34, 35 whichsupport most of the mechanism of the recorder, either directly orthrough suitable brackets or sub-frames carried by said plates 34, 35.Two frames 36, 31 support a time stamp printing head which issubstantially'the same as the one described in Letters Patent NoI1,798,583 granted March 31, 1931 to L. C. Bishop and A. L. Sprecker. Asthis printing head is now well known in the art and fully described inthe above patent, no detailed description of its construction andoperation need be given herein. It will be sufiicient to remark that amagnet TM (Figs. 4 and '7) actuates time printing type wheels 38 (Figs.1 and 4) which print the hour and minute. The letters AM or PM areprinted by a type wheel 39, the year by a type wheel 40, while the monthand day are printed by type wheels 4|, 42, respectively. The magnet TMreceives regular impulses of current occurring once each minute andtransmitted by means to be described later. The magnet TM also drivesthe hands 43 which, with a suitable clock dial, indicate the timevisually through glass panel 32.

The strip chart 33 is unwound from a supply spool 44 loosely mounted ona shaft 45 journalled in the plates 34, 35 (Figs. 3 and '4). This shaft45 is removably mounted to permit new rolls of chart to be inserted asneeded. The strip chart 33 passes upwardly beneath a paper guide plate46 and over a sleeve or roller 41 (Fig. 4) on a cross shaft 48 carriedby plates 34, 35; over a cross shaft 49 also supported by said frames;forwardly over a feed drum 50; and thence downwardly to the storagespool 5|. The feed drum 50 is secured to a shaft 52 (Figs. 1, 3, and 4)which is journalled in frames 34, 35 and said drum has at its endssuitable sprockets 53 engaging holes 54 in the edges of the strip chart33. Secured to the right-hand end of shaft 52 (Fig. 1) is a gear 55 bymeans of which shaft 52 anddrum 50 may be rotated to feed the stripchart.

The frames 36, 31 which support the printing wheels 38 to42 aremountedon rectangular blocks 56 (Fig. 4) secured to plate 30, and overhang theleft half of the strip chart 33 (Fig. 1) which passes between an inkingribbon 5'! and a platen 58 of resilientmaterial. The platen 58 iscarried by a cross bar 59 channel shaped in section (Fig. 4) and affixedto the upper end of the plunger 60 of a solenoid TPS, hereinafterto betermed the time printing solenoid. The latter has a U- shaped fieldpiece 62 (Fig. 1) secured to the right hand side of frame 34. Both legsof field piece 52 are slotted as at 63 (Fig. 4) to guide tongues 64 in arectangular plate 65 secured to the lower end of the plunger 50. By thisconstruction the plunger 60, which is circular in cross section isprevented from rotating yet is free to move vertically a limited amount.Solenoid TPS is energizedby means hereinafter to be described and whenthis occurs the platen 58 is propelled rapidly upward (Figs. 1 and 4) toforce-the left-hand half of the strip chart against the printing wheels38.to 52 of the time stamp printing head thus printing on the chart, themonth, day, year, and time in hours and minutes.

The records of operation of circuit breakers, processing machines, andthe like are made by a bank of type elements to the right of the typewheels 38 to 42 and in alignment with those type faces of said typewheels which confront the platen 58. Each machine or device whoseoperations are to be recorded has associated therewith a pair of typeelements 66m and 661), there being in the illustrative embodiment of theinvention, ten pairs of type elements, or a total of twenty elements.

The ten pairs of type elements 66m, 65b are vertically slidable in slotscut in a frame 61 (Fig. 6) secured to a frame 68 whose left-hand end(Fig. 1) is supported by a bracket 69 secured to frame 31 and whoseright-hand end is supported by a bracket 10 secured to plate 35. A plateH mounted in grooves in frame 61 holds the row of type elements 66m, 66bin the frame 61 but permits them to be depressed against the tension ofsuitable springs (not shown in Fig. 6) within the box-like frame formedby plate H and frame 61.

The type elements 66m have M types on their lower ends while the typeelements 661) are similarly provided with B types. These letters, in theillustrative embodiment of the invention represent the words make andbreak, respectively. Obviously each pair of type elements can beprovided with other suitable letter type such as S for start and F forfinish, O for open and C for closed, and so on, to suit the purpose forwhich the recorder is being used. For convenience in "description it maybe assumed that each pair of type elements 66m, 661) is associated witha circuit breaker or oil switch in an electric power system and that thepairs of type elements are numbered I to H1 from left to right (Fig. 1)to correspond with the ten vertically ruled columns in the right-handhalf of the strip chart 33 in Fig. 5.

Mounted on the left-hand side of plate 35 and extending horizontally tothe left (Fig. 1) beneath all the type elements 65m, 66b is a bar 12provided on its upper side with a channel shaped member 13 carrying astrip 14 of resilient material forming a platen (see Fig. 6). half ofthe strip chart 33 passes over the platen I4 and beneath the inkingribbon 51 which, of course, is interposed between the faces of the typesin elements 66m, 6622 and the strip chart 33. Thus movement of anyselected type element of a pair 66m, 66b downwardly (Fig. 6) will causethe chart 33 to be imprinted in the column corresponding to the selectedtype element.

The type elements 66m, 661) of the different pairs are selected foroperation by means of ten interposers 15 having the general. shape shownin Fig. 6. Each interposer is associated with a pair of type elements65m, 661) and is secured to The right-hand brackets 11 making. angles ofsubstantially so that the attraction of an armature I8 by its interposermagnet causes the corresponding interposer I5 to swing horizontally tothe right (Figs. 1 and 6). Normally the interposers I5 overlie the headsof the type elements 96m as shown in Figs. 1 and 6 but, when swung asdescribed, move to a position over the heads of the type elements 86b.selected interposer magnet causes its interposer I5 to swing to theright (Fig. 6) from a position over the type element 88m of the pairassociated with the selected magnet to a position over the type element86b ofthe same pair. The interposers I5 are guided and restricted intheir movements by notches or slots 88 formed in the frame '88 as shownin Fig. 6. The rods I6 are sufficiently resilient to permit theinterposers 15 to be moved downwardly a slight amount. by hammermechanism presently to be described.

The magnets are arranged in three groups for sake of compactness, twogroups (magnets IMI to IM4and IMI to IMI8) having four magnets and onegroup (1M5, 1M8) having only two magnets. Only two groups are shown inFig. 3 and of these only one magnet of each group is shown. Theinterposer magnets of the left-hand group in Fig. 3 are secured to aframe 8| which is L- shaped in transverse section or as viewed from theupper end (Fig. 10) and slotted to form four posts or tongues 82 towhich are pivoted the armatures I8 by means of a rod or wire 83 securedin grooves cut in tongues 82.

Associated with each interposer magnet and secured to frame BI is a post84 opposite a short pin 88 on the adjacent armature I8, which post 84acts as a stop for armature 18 and also guides a spring 89 normallytending to hold armature 18 away from the pole of its magnet.

One of the ears 81 by means of which each armature I8 is pivoted on wire88 is extended to the right (Fig. 10) to one side of the adjacent tongue82 and acts as a stop to prevent armature I8 from moving too far awayfrom the pole of magnet I9. The frame 8| is mounted on posts 88 securedto frame plate 38. The other group of four magnets (IMI to IM4) issimilarly constructed and mounted behind the group of four magnets IMIto IMI8 designated in Fig. 3. The

group of two interposer magnets 1M5, 1M6 designated in Fig. 3 issimilarly constructed but its friame 8| is mounted directly on the frameplate 8 The interposer magnets are individual to the machines, devices,or apparatus whose operations are to be recorded. Thus, in the case ofthe illustrative embodiment of the invention there is an interposermagnet corresponding to each circuit breaker and consequently a pair oftype elements 88m, 68b associated with each magnet and its circuitbreaker. The manner in which the interposer magnets IMI to IMI8 areselected for operation will be explained in detail later herein.

The hammer mechanism is best shown in Figs. 1 and 3. Associated witheach pair of type elements 86m, 882) and their interposer, is a printinghammer. 89. Hammers 89 are pivoted on a cross rod 98 carried by the armsof a bail 9| which is fixed to a shaft 92 journalled in frames 98mounted on frame plate 88. A spring 94, anchored to pins carried by bail9I and frame 93 normally holds the arms of bail 9| down against a rod 95carried by frames 93.

The cross bar of bail 9I has slots open at the bottom to form a combguiding the hammers 89 In other words, energization of any and hasrearwardly and upwardly extending lugs 96 to which are secured springs91 anchored to ears 98 formed in the hammers 89. The springs 91 normallyhold the hammers 89 up against the bail 9| and out of contact with theinterposers I5. .Each hammer 89 is wide enough to strike the associatedinterposer 15 when the latter is in either of its two possiblepositions.

Secured to shaft 92 is an arm 99 projecting downwardly into engagementwith a shoulder in a link I88 pivoted at IN to an arm I82 on shaft 48.The arm I82 is secured to an arm I83 fixed to shaft 48, The right-handend of link I88 has a pin extending into a slot formed in an arm I84pivoted at I85 to frame 93. A spring I86 interposed between the pin justmentioned and a pin on frame 93 normally holds said pin in the upper endof the slot in arm I84 as in Fig. 3. An arm I81 secured to shaft 48, hasa pin and slot connection to the plunger I88 of a solenoid MIB,hereinafter to be termed the make and 'break printing solenoid." PlungerI88 is as usual in solenoids of this type freely movable in a tube I89surrounded by the coil of the solenoid MPB.. The latter is of the ironclad type and is supported on two cross rods II8 extending betweenplates 34, 35. Secured to the lower end of plunger I88 is a flanged stopIII of nonmagnetic material which stop limits upward movement of plungerI88 caused by a spring II2 attached to arm I82 and a stud carried byframe 98. I

When solenoid MBP is energized in a manner hereinafter to be described,plunger I88 is drawn downwardly, rocking shaft 48 counterclockwise (Fig.3) and causing link I88 to be drawn to the left in said figure. Arm 99,shaft 92, and bail 9| are rocked clockwise as a unit by the cooperationof link I88 and arm 99, raising the printing hammers 89, spring 94 beingtensioned as the bail 9I rises. As link I88 moves to the left, link I84,cooperating with the pin on link I88, gradually forces the right-handend of link I88 downwardly until finally the shoulder on said linkbecomes disengaged from arm 99.

Ball 9I is now drawn downward rapidly by spring 94 until said ballstrikes cross rod 95. The momentum of the heads of printing hammers 89,however, causes the latter to move below their normal position of Fig.3, against the tension of springs 91, and strike the interposers I5percussively. Downward movement is thus imparted to the type elements68, 66b underneath the interposers causing said type elements to printon the chart. The springs 91 then restore the printing hammers 89 to theposition of Fig. 3. Deenergization of the solenoid MBP causes springsI88, II2 to restore the parts connected to said springs and link I88 to.the positions shown in Fig. 3.

It is evident that ten type elements 68m, 88b will be operated each timesolenoid I89 is energized and will print a. row of letters transverselyof the left half of the strip chart as in the case of the lowest row inFig. 5. The printing of the letter M" in any of the numbered verticalcolumns of Fig. 5 signifies that the circuit breakers or oil switchescorresponding to such columns were closed by the operations which causedthe printing operation, while the presence of the letter B in any columnmeans that the corresponding circuit breaker or oil switch was opened.

The mechanism for feeding a predetermined length of stripchart in apredetermined length of time will now be described in detail. Thisarsavea mechanism is best illustrated in Figs. 1, 2, 14, 15, 16, and1'7.

The chart feeding mechanism is driven by a motor DOM which is operatedby direct current and is designed to operate at a constant speed. Themotor, by itself, forms no part of the present invention and need not bedescribed in detail herein. It will be sufficient to state that it hasbeen especially designed for use in clocks or timing devices where thespeed must be as near constant as possible and has a negligibleacceleration period before it reaches full speed, attaining full speedin a small fraction of a second. It is mounted on the right hand side ofplate 35 and has, as an integral part thereof, a gear casing l Mcontaining suitable reduction gears which turn in a bath of oil.

A short shaft l l5 extends horizontally from the gear casing lit in adirection transverse of the longitudinal axis or" the motor. Thereduction gearing is so designed that shaft H5 turns at a uniform rateof two revolutions per minute.

The shaft l l5 carries a pinion lit meshing with a gear l it havingtwice the diameter of said pin-' ion-so that a shaft lit to which gearill is secured will be driven at the rate of one revolution per minutewhen the motor DCM is in operation. Shaft H8 is journalled in a plate 35and in a sub-frame M9 secured to plate 35 and extends to the left(Fig. 1) beyond gear on the shaft 52 carrying the drum 5t. Secured toshaft M8 is a ratchet wheel G2 which is part of a clutch mechanism forcoupling the shaft M8 to a pinion lit which meshes with gear 55. Thepinion iii (see Fig. 17) is secured to a sleeve i212 which is loose onshaft i it and extends through frame 35 to the side of ratchet wheel 6%.

Adjacent ratchet wheel E25 a hub 123; is fixed to sleeve i22 and securedto this hub are two arms are, 525 (Fig, 16). Pivoted at 125 to the armi2? is a three arm lever or clutch dog 621 one of whose arms H28normally engages a hook formed in an arm ltd (Fig. 14) in which positiona bent over bevelled lug l3il on one arm of dog 12'! is clear of theteeth in the ratchet wheel. A spring 3!], interposed between a pin 32 onarm 25 and an ear in one arm of dog Hill, tendsto rock dog it? clockwisebut such action is normally prevented by the hook in arm E29. When thelatter is rocked counterclockwise (Fig. 14) to the position of Fig. 15,the spring E35 will draw the lug 930 of dog l2? into engagement with theteeth in ratchet wheel llll thereby coupling arm E25 and sleeve in tothe ratchet wheel lid and shaft H8. If now the motor DCM is started, thedrum 50 will be rotated by shaft H8 through gear.55, pinion I2I, sleeveI22, arm i25, dog I21, and ratchet I20.

Near the end of a full revolution of arm 125.

the arm I28 will reengage the hook in lever E29 and be rockedcounterclockwise back to the position of Fig. 14 whereby co-disengagelug I30 from the ratchet. Thus, a single revolution is imparted tosleeve I22 and pinion I2I anddrum 5| is turned a. half revolution. Inthe illustrative embodiment of the invention a half revolution of drum5!) feeds the strip chart a distance of exactly one and one-half inches.Since shaft "8 revolves at a constant speed of one revolution perminute, it is obvious that'the strip chart will be fed at the rate ofone and one-half inches per minute or inch per second.

' A friction spring or washer I33 (Fig. 17) is interposed between armI25 ,and ratchet I20. The purpose of this element is to ensure reliableoperation of the clutch mechanism and accurate feed of the chart whenthe dog I2! is approaching relatching position. The spring I3I also hasa tendency to rock the lever l2! clockwise from the position of Fig. 14and, if no means were provided to prevent such movement, the arms I24,I25, sleeve I22, and parts connected thereto, including the chart feeddrum 50 might be reversely rotated enough to cause erroneously locatedimprints on the chart and consequently errors might be made ininterpreting the entries on the chart.

The friction washer or spring i133 exerts sufficient pressure betweenarm I25 and ratchet I 20 to prevent this reversemovement and alsoensures that the arm I25 will move far enough as the motor DCM coasts toa stop, to carry the clutch lever arm I28 fully to latching position andcomplete the feed of the chart. At this point a long tail or arm of thelever lZ'l strikes the pin l32 and prevents the coasting or" the motorfrom carrying the arm l25 beyond the normal latched position in Fig. 14.Thus shaft i it cannot drive arm will be termed the starting magnethereinafter as a matter of convenience. This magnet is secured to theright-hand side of plate 35 (Figs; 1 and 2) and actuates an armaturellitl fixed to an arm E35 pivoted at 1136 to frame 35. A link i3? ispivoted to arm 335 and to an arm 638 fixed to a shaft I39 journalled inframe iii) and plate 35. The arm i291 is secured to shaft l3?) andobviously said arm will be rocked counterclockwise (Figs. 2 and i l)whenever starting magnet SM is energized in a manner hereinafter to bedescribed. Also secured to the right-hand end of shaft 539 (Fig. l) isan arm Mil to which is attached a spring Ml anchored in frame M9. Thisspring tends to rock arm 64, shaft 339, and arm 29 in a clockwisedirection (Figs. 2 and 14) and thus normally holds arm are in latchingengagement with arm l2il of lever 82?.

Magnet SM also controls certain contacts designated MDI, MDZZ, and MDB(Figs. 1, 2 and 15) which, for convenience, may be called the minuteduration contacts'as they are held in operated position for exactly oneminute while shaft 153 is turning to feed the strip chart 33. ContactsM133 are normally closed while contacts MDl, MD2 are normally open.These contacts are carried by and insulated from a bracket M2 secured toplate 35 (Figs, 1 and 2). Thearm l24 (Figs. 14, 15 and 16) has pivotedthereto at M3 a cam dog l44. A spring 545 anchored to pin I32 (whichpasses through both of the arms 324, M5) and to an ear in lever I44tends to hold the cam lever I44 in the positions of Figs. 14 and 16where a pin I46 limits counterclockwise movement of the cam dog inresponse to the spring I45. The cam dog I44 alsohas a cam lug I41adapted to cooperate with a similar but reversed cam lug in the upperend of a lever I48 (Figs. 2, 14, 15 and 16) pivoted at I49 to a frameI50 secured to plate 35.

Normally the parts occupy the position of Fig. 14. In this position, apair of insulating disks I5I, secured to the lower end of lever I48(Figs. 1, 2, and 14), engage the minute duration contacts MDI, MD2, MD:in such fashion as to hold MD3 closed and MDL'MDZ open as in Fig. 2.When cam dog I44 is moved upwardly. the position of Fig. 15 so that camlug I4I'clears the cam permitted to rock slightly in a clockwiseposition by spring action of the minute duration contacts MDI, MD2, MD3so that the first two close and the last opens as shown in Fig. 15. Inthis position of the parts a lug I52 on the front part of frame I50engages lever I48 and limits its clockwise movement. The minute durationcontacts are purposely made of thin resilient conducting material topermit the described action.

The cam dog I44 is moved upwardly when the armature I34 of magnet SM isreleased. Shaft I39 has an arm I53 secured thereto which arm curvesforwardly to the left (Figs. 2, 14 and 15) and upwardly. A link I54 ispivoted to the arm I53 and is urged in a clockwise direction by a springI55 anchored to arm I53. Normally link I54 bears lightly against abent-over lug I56 formed in cam dog I44 with a notch or shoulder I51formed in the upper end of said link just above the lug I56.

When magnet SM is energized shaft I39 and arm I53 are rockedcounterclockwise (Fig. 14) drawing down link I54 a distance sufilcientto bring shoulder I51 slightly below lug I56 thereby permitting the linkI54 to rock slightly clockwise under the influence of spring I55 tobring shoulder I51 under said lug. This movement of link I54 is limitedto the necessary degree by a projecting part of frame I56.

The subsequent deenergization of magnet SM permits spring I to restorethe arm I53 to the position of Fig. 14 with the result that the link I54rises and shoulder I51 engages lug I56 and lifts the latter rocking dogI44 clockwise to the position of Fig. 15 which movement of the dog is-sufficient to move cam lug I41 up out of contact with the corresponding,lug in lever I48. This action results in the urination of minuteduration contacts MDI, MD2, MD3 as'described.

The purpose of the construction just described is to secure extremelyrapid operation of the contacts MDI, MDZ MD3 before the motor beginsdriving the chart. Obviously the minute dura tion contacts could beoperated by a simple cam on shaft I I8 but in such case a time delaywould inevitably result as said shaft turns at such a slow rate that thechart would be fed'for several seconds before the cam could become fullyef fective to operate the contacts. When the de scribed construction isused the duration contacts MDI, MD2, MD3 are operated at the verybeginning of the chart feed. Magnet SM is energized momentarily only andobviously the chart 38 begins to feed and the minute duration contactsare operated practically simultaneously. Near the end of each revolutionof shaft H6 and arm I24, I25, the cam lug I41 reengages thecorresponding ing in lever I48 and restores the minute duration contactsto their normal position of Fig. 14.

- The magnet TM which actuates the type wheels 38 of the time stampprinting head is energized once each minute by a clock movement ortiming unit which normally is driven by an alternating current motor ofthe synchronous type now commonly used in electric clocks. This motor isdesignated ACM in Figs. 2, 12 and 13 and is mounted on a. plate I58 bymeans of screws like I59 (Fig. 12) which pass through the plate I68,sleeves like I88, the field frame of motor ACM and are threaded intoshouldered sleeves I6I. The plate I I58 is screwed to plate 36.

The shoulders in sleeves I6I support a frame I82 which has mountedthereon a clutch magnet CM and its fleld piece I64. Spaced from frameI62 by means of sleeves I65 carried by the shoulders in sleeves I6I is across bar I66 which acts as a steadying support for the shaft I61 ofmotor ACM. This shaft projects from the gear casing I 68 of the motorACM and drives'a toothed clutch element I69 fixed to said shaft. Thecross bar I66 is secured to the left-hand sleeve I6I (Fig. 13) by meansof a screw I10 and to the righthand sleeve I6I by means of a threadedstud Ill hexagonal in section screwed into the sleeve I6I.

The stud I1I, together with a cross rod I12 secured to a part of frameI62, together support a frame plate I13. The latter supports the rearend of a. shaft I14 which is coaxial with shaft I61 and said plate alsosupports contacts designated CC which will be termed the clutchcontacts. Secured to the right-hand end of shaft I14 is a toothed clutchmember I15 similar to clutch member I69.. Jointly supported by theshafts I61, I14 between clutch members I69, I15 is an assemblycomprising two toothed clutch members I69a, I15a coacting with clutchmembers I69, I15, respectively; a cam I16, and a grooved portion formedby two flanges I11. Normally clutch elements I69, I69a are kept in.clutching engagement by means of a clutch shifter element I18 whichextends into the groove formed by the flanges I11 and is secured to thefree end of the armature I19 of magnet CM.

The armature I19 is pivoted on a knife edge I formed in the front end ofthe upper horizontal leg I8I of field piece I64, suitable lugs I82 inthe leg 8| loosely projecting into notches cut in armature I19 toprevent the latter from being displaced from said knife edge. The upperend of armature I19 has a tongue I83 connected by a coil spring I84 to abracket I85 secured to the leg I8I. This spring normally has a tendencyto rock armature I19 and shifter element I18 in a clockwise direction(Fig. 12) but energization of magnet CM normally prevents actualmovement of the armature in response to said spring. The motor ACM andthe magnet CM are in parallel across line wires WI, W2 leading to asource of alternating current AC (see Fig. 7) and normally the motor isrunning as in any electric clock. It is plain ithat as long as currentis supplied to motor ACM it will drive the assembly including clutchelement I69 and cam I16. The gearing in casing I68 and the synchronousspeed of the motor ACM are so chosen that normally shaft I61 and hencecam I16 will rotate at a constant speed of one revolution per minute.

Secured to the armature I19 is an arm I86 which extends forwardly (tothe left in Fig. 12) to a point underneath the lower contacts CC. Whenarmature I19 is released by deenergization of magnet I63 caused bycessation of flow of the alternating current, an insulating button onarm I86 presses the lower contact CC into engagement with the uppercontact. The clutch contacts CC are provided to close the circuit to thedirect current motor DCM whenever the supply of alternating current isinterrupted. The control effected by contacts CC will be explained morefully hereinafter.

I88 to plate I13 and a three-arm cam'follower I89 pivoted at I90 to' camfollower I81. A spring I9I secured to one arm of cam follower I89 and.to plate I13 normally holds both cam followers in contact with cam I18.One arm of cam follower I89 has an insulating disk I92 which underliesone of the contacts MIC. The extreme righthand end of cam'follower I89does not extend quite as far to the right as the cam follower I81 asshown by the broken line in Fig. 13. As cam I18 turns in a clockwisedirection in said figure, it is plain that cam follower I89 will dropinto the dwell in cam I18 before the cam follower I81 thus permittingspring I9I to rock cam follower I89 clockwise lifting disk I92 andforcing contacts MIC to close. Subsequently, cam follower I81 will dropinto the dwell and spring I9I will rock said cam follower clockwiseallowing disk I92 to drop thus permitting contacts lVHC to reopen. Atthis time cam follower I89 also is rocked slightly counterclockwiserelative to cam follower I81. The contacts MIC are not materiallyaffected by the cam I18 as long as both have the relationship of Fig.l3as the simultaneous lifting of both cam followers merely cause disk I92to travel in the arc of a circle whose center is at I88 immediatelybelow contacts MIC so that the latter are moved but slightly except whenthe dwell in the cam causes relative movement between the cam followers.

The shaft I14 extends forwardly (to the left in Figs. 2 and 12) to apoint above and rearwardly of shaft II8 where shaft I14 is journalled ina bracket I93 secured to frame II9. A gear I94 is secured at this pointto shaft I14 and meshes with a gear I95 pivotally mounted on the bracketI93. The gear I95 meshes with a gear I95 fixed to shaft H8. The drivingratio of gears I94, I95, I98 is unity therefore shaft I14 will be drivenat the constant rate of one revolution per minute whenever motor DCM isin operation.

Normally motor ACM drives the .cam i118 but an interruption in thesupply of current to said motor causes clutch magnet CM to becomedeenergized whereupon spring I84, through shifter I18 causes theassembly comprising clutch elemerits I89a H50 and cam I18 to shift tothe left (Fig. 12), disengaging elements I69, I89a and engaging elementsI15, I15a. At the same time, clutch contacts CC close thereby energizingmotor DCM (Fig. '1) which will then drive cam I16 at the same speed asmotor ACM drove it, through gearing I94, I95, I98, shaft I14, and clutchelements I15, I15a. This driving connection to motor DCM will bemaintained until the supply of alternating current to motor ACM isrestored causing clutch magnet CM to reengage.

clutch elements I89, I89a.

Mechanism is provided for automatically feeding the inking ribbon 51 andis shown in detail in Figs. 1, 2, and 21. Secured to the right hand sideof frame 35 is a frame I91 which supports the ribbon feeding mechanism.Pivotally mounted on the front face of this frame I91 i (Fig. 21) aretwo ribbon spools "8B. and I981.

respectively, each spool being removably secured to a shaft I99journalled in the frame I91. The rear ends of shaft I99 have securedthereto gears 200R and 200L (Fig. 20) by means of which said shafts andtheir spools may be driven.

The ribbon 51 is secured to eachspool and from the right hand spool I98R(Figs. 1 and 21) the ribbon passes over a guide pulley "I carried byframe I91; to the left across the top of the recorder over a pulley 202carried by frame 38;

. chart 33.

downwardly to a pulley 203 on a shaft 204; thence to the right beneathtype wheels 38 to 42 and type elements 88m, 88b; over a pulley 205carried by a frame 208; and over a pulley 201 carried by frame I91, tothe left hand spool I98L. Pulleys 203 and 205 are adapted to be movedforwardly for a purpose to be described later. For the time being itwill be assumed that the last named pulleys are in their rearmostpositions in which the front half (or left hand half, Figs. 2 and 6) ofthe ribbon 51 lies beneath the type faces of elements 88m, 8811 and typewheels 38 In order to prevent smudging of the chart 33 there is provideda ribbon guard 208 (Figs. 1 and 6) which extends across the recorderbetween frames 34 and 35 and between the ribbon 51 and This guard hastwo rectangular openings, one opposite the type faces of elements 68m,881), and the other opposite the type faces of type wheels 38 to 42.

Journalled and slidably mounted on lugs 209 in frame I 91 is a shaft 2I0carrying gears 2IIR I91 and secured to said shaft 2|8 is an arm 2I1connected by a link 2I8 to an arm 2I9 secured to a shaft 220.' Thelatter is journalled in frames 34, 35. An arm 22I secured to shaft 220has a slot embracing a pin 222 carried by an extension 223 of theplunger 88 of solenoid TPS (Figs. 1 and 4) Obviously links 2 I4, 2I8will be drawn downwardly each time the solenoid TPS is energized to drawup its plunger 80.

Arm 2H3 carries a feed pawl 224 operated by a spring 225 (Fig. 2) andeach time link H4 is drawndownwardly by an operation of solenoid 'I'PSthe ratchet wheel 2I2, shaft 2I0 and one of the ribbon spools will berotated at step thereby feeding the ribbon 51 an increment,

The shaft 210 is automatically shifted to reverse the feed bymechanism-best shown in Figs. 20 and 21. Journalled in frame I91 beneaththe shafts I99 are shafts 226 having secured thereto. in front of frameI91, arms 221 provided with rollers 228 bearing on the coils of ribbon51 wound on the spools I98R, I98L. The rear ends of shafts 228 havesecured thereto arms 229 (Fig. 20) secured to whicil' are flat leafsprings 230. Pivoted at 23I to frame|91 are rock levers 232 each havinglugs 233 one of which is pressed against the adjacent end of shaft 2I0by contact of leaf spring 230 with the other lug. I

Each rock lever 232 has a bent over lug 234 adapted to cooperate with alocking notch 235 in a latch 238 pivoted at 231 to frame I91. The lugs234 project into the planes of latches 238 and springs 238 anchored tolugs 209 cause the latches 238 to press on lugs 238. Arms 229 areintercbnnected by a spring 239 and have lugs 240 projecting into theplanes of latches 238. The spring 239 constantly tends to rock shafts229 in such fashion as to cause rollers 228 to press on ,the coils ofribbon on'the spools I98R and I981... I

As fie ribbon becomes wound or unwound from the spools, the arms 221,shafts 226, and arms 229 will be progressively rocked and lugs 246 willfall or rise according to whether the associated spool is winding orunwinding the ribbon. To prevent reverse movement of ratchet 212 thereis secured to frame I91 a leaf spring 24! the free end of which engagesthe teeth of said ratchet.

one, Fig. clockwise.

Normally the notch 235 on the latch 236 of the spool which happens to bewinding the ribbon is disengaged from its lug 234 as in the case of thelatch for spool |9BR in Fig. 20 while the notch 235 of the other latch236 is engaged with its lug 234 as in the case of spool I98L in Fig. 20.Take the illustrative example of Figs. 20 and 21. As spool IBBR windsthe ribbon 51, arm 221 is gradually rocked counterclockwise (Fig. 21)thus rocking the associated arm 229 (the left hand This causes spring230 to press arm 232 against the end of shaft 2l0 with increasingpressure as the spool 198R accumulates the ribbon. The arm 229 of spooli93L will also be rocked in a clockwise direction (Fig. 20) as saidspool unwinds so that the pressure of spring 230 of spool |96L on thecorresponding arm 232 is gradually lessened. No lengthwise movement ofshaft 210 is permitted however, as the notch 235 in latch 236 of spoolI98L at this time is securely holding its lug 234. Obviously lug 240 ofthe right-hand am 229 in Fig. 20 will gradually rise as the ribbonbecomes unwound from spool |96L and eventually, when the ribbon becomesnearly completely unwound from spool I36L, will lift latch 236, freeingnotch 235 from lug 234, and permitting the left-hand leaf spring 230 toshift the upper end of left-hand lever 232 and shaft 2) to the right(Fig. 20') thereby meshing the gears 200L, 2III- and demeshing gears21108., NIB. At the same time lug 235 of the right-hand latch 236associated with spool I96R will engage its lug 234 and hold the latch236 and shaft 2H1 in shifted position.

The spool-i96L will now be driven by shaft 2| 6 and when this spoolbecomes full, the parts will be automatically shifted back to theposition of Fig. 20 in exactly the same manner as described above.

There is provided a control switch designed to be attached to eachcircuit breaker, device, machine, 'or apparatus whose operations are tobe recorded on the chart 33. This switch is illustrated in Figs. 9, 18and 19. As the service to which these switches are to be subjectedislikely.

to be severe, they are purposely very ruggedly constructed and housed ina strong protective case capable of withstanding considerable abuse.

The mechanism of the switch is mounted on a one piece base casting 242having two upstanding lugs 243 and a relatively wider lug 244 supportingtwo pairs of spring contact members designated H and M. These contactswill be termed the holding contacts and momentary con-' tacts,respectively. Both pairs of contacts are alike in construction anddiffer only in the manher of their operation. Contacts H are carried bytwo flat spring members 245 insulatably mounted upon lug 244. One ofthem is slightly bent toward the left (Fig. 18) to provide a spring biassufficient to separate the contacts H and has secured thereto a button246 of insulating material which presses upon a leaf spring member 241also mounted on lug 244 by means of the screws 24. securing members 245to said lug. Member 241 is also slightly bent to the left to provide aspring bias like the member 245, and bears against a slightly curvedstop strap 246 secured .243 is a collar 26!.

to lug 244 by screws 248. A bent-over lug 249 formed in member 241carries a cam roller 250 adapted to cooperate with a cam 25! foroperation by the latter.

The contacts M are similarly mounted and are adapted to be operated by acam 252 having a shape diilerent from that of cam 251. The cams 25l, 252are rocked in one direction or another, according to the operation ofthe device to which they may be connected by means of a shaft 253journalled in the lugs 243. The lefthand end (Fig. 19) of this shaft isprovided with a key-way 254 as a convenience in connecting shaft 253 tothe device which operates it, a suitable arm keyed to said shaft being alikely type of connection.

Secured to shaft 253 is a hub 255 on a shoulder of which is looselymounted a member 256 (Figs. 9 and 19) and secured to another shoulder onsaid hub is a member 251. The shoulder supporting member 251 is slightlysmaller in diameter than the shoulder carrying member 256 and isdirectly to the right of member 256 (Fig. 19). Member 256 has twoprojections 258 adapted to engage a pin 259 carried by the left-hand lug243. The projections 256 are so spaced that member 256 is capable ofrocking an angular distance of 90 which movement is limited by pin 259.Member 256 also has a bent-over lug 260 (Fig. 9) projecting into a notch261 formed in member 251 so that movement of members 256, 251 relativeto each other is restricted by the width of the notch 261. Member 251has two ears 262 on opposite sides of shaft 253 which ears are connectedby springs 263 to a lug or arm 264 forming part of member 256. Thesprings 263 are balanced as to tension so that normally lug 260 has aposition midway between the side walls of notch 26| as in Fig. 9. It isplain that, as long as clockwise rotation of shaft 253 is confined to anangular distance of 90 from the position of Fig. 9, the members 256, 251will move as a unit a similar angular distance, and the lug 260 willremain in the center of notch 26l. The same remarks apply to the case ofcounterclockwise movement of shaft 253 from a position where pin 259 istouching the upper or left hand projection 256.

Loosely mounted on shaft 253 between hub 255 and the right-hand lug 243(Fig. 19) is a sleeve 265 which has an enlarged portion 266 adjacent hub255 and, incidentally, is journalled in right hand lug 243 and hencesupports shaft 253. Loosely mounted on sleeve 265 adjacent the enlargedportion 266 is a hub 261 to which is secured cam 252. A pin 266, carriedby arm 264 of member 251 projects into a hole in cam 252 so that thelatter and member 251 move as a unit. Pinned to sleeve 265 adjacent theright-hand lug The cam 251 is loosely mounted upon sleeve 265 betweentwo friction washers 215 and a friction spring 211 is interposed betweenhub 251 and the left-hand friction washer 216. The effect of frictionspring 2 is to press hub 261 against the enlarged portion 266 of sleeve255 and to press cam 25! against the right-hand friction washer 210which, of course, in turn presses against collar 269. Obviously cam 25lis frictionally connected to members 256, 251

The profile of cam is such that it is in advance of cam 252 when theparts are in the position of Fig. 18 and is adapted to operate uponroller 249 to close contacts H and hold them closed when the cam isrocked clockwise the full extent permitted by pin 212. Cam 252, on theother hand, has a profile such that contacts M are open at both thebeginning and end of the 90 of movement of this cam permitted by pin 259and are closed for a period of approximately roughly speaking, in therotation of the cam. Figs. 9, l8 and 19 show the positions occupied bythe various parts of the control switch when the circuit breaker, oilswitch or similar device or apparatus is in closed circuit condition orin full operation as the case may be. This, of course, is a purelyarbitrary arrangement.

When shaft 253 is rocked 90 in a clockwise direction (Figs. 9 and 18) asby the operation of a circuit breaker to open a circuit, the entireassembly on this shaft rotates as a unit with the shaft.

The first 15 of movement of shaft 253 results in closure of contacts Hby cam 25!. The pin 212 then strikes the right side wall of notch 213(Fig. 18) and prevents further movement of cam 25! in a clockwisedirection. Cam 252, however, is

still free to move and, during the next 30 of movement, first closesthen reopens contacts M.

I At the end of 90 of movement contacts H will have been closed andcontacts M opened, cam 252 will have been displaced 90, while cam 25!will have been displaced 15 relative to cam 252.

The amount. of the foregoing displacement of cam 25! relative to cam 252is so designed that a counterclockwise movement of shaft 253-from thelast described position, caused by operation of a circuit breaker orswitch to close a circuit, will cause the roller 250 of cam 25! to dropinto the dwell of said cam before cam 252 is operative to close contactsM. In other words, in the case of counterclockwise movement of shaft253, the first 15 of movement results in opening contacts H, then thecontacts M are closed and reopened and cam 25! displaced relative to cam25! back to the position of Fig. 18 during the next 30 of movement. Theremaining 15 of movement in both cases are idle. I

The springs 263 provide .a flexible connection between members 256, 251which permits shaft 253 to turn slightly more than 90 in either direc-In order to exclude dust and moisture as much.

as possible, the switch described above is protected by a removablecover 214 secured to the base 242 by means of screws 215', a gasket 216interposed between the cover 214 and base 242 providing a moisture anddust proof seal. A close fitting slot 211 in cover 214 permits theremoval of the cover without disturbing shaft 253.- This slot may beclosed by a dust and moisture-proof cover, if desired. v

Means is provided to print opposite each line of impressions from therow of type elements 66m, 66b, an arrow or other special sign whichindicates the first impression made on each predeof a three arm lever280 pivoted on an extension of plate 218 (Fig. 11). Another arm of lever280 extends rearwardly over the head of a type element 28! like typeelements 66m, 66b and similarly mounted in frame 61 and plate 1!. Aspring 282 normally presses type element 285 upwardly, this constructionbeing the same as that of elements 66m, 66b. The type element 28E has atype character on its lower end capable of printing the bent arrowsshown in Fig. 5 and is located slightly to the left (Figs. 1 and 8) ofthe extreme lefthand type element 66m. A spring 263, anchored to a lug280 in the frame of solenoid APS and attached to the third arm of lever280 normally holds said arm against a lug 285 in the frame of thesolenoid.

Obviously energlzation of solenoid APS will 11) to force type element282 downwardly into contact with the inking ribbon 51 thus making theimpression of a bent arrow alongside and in line with the impressions oftype elements 66m, 6627 as in Fig. 5. The arrow printing solenoid isoperated only when the initial.entry is made on each predeterminedlength of chart and is controlled in a manner to be explainedhereinafter.

Means are also provided to cause the operation of the recorder when thecase 8! is removed for any reason which means is so arranged that therecords made under such circumstances are in-a color sharply contrastingwith the records made during normal operation. ,Figs.'1, 2.4, and 21best illustrate the above means. The ribbon 51 is a two-color ribbon ofconventional form in which the left-hand or front half of the ribbon(see Fig. 6) may be charged with blue ink while the right-hand or rearhalf may be charged with red ink. Normally the front or blue half of theribbon is beneath the faces of the types at the printing line butremoval of the case 3! is designed to cause the ribbon 51 to shift tothe left (Figs. 2 and 4) to bring the rear half of the ribbon under thetype faces. For this purpose the ribbon guide pulley 203 is rotatablymounted on a rod or shaft 204 but cannot slide on said shaft. Thelatteris slidably mounted in brackets 286, 281 secured to the left-hand sideof frame 36 and has a head 288 secured thereto which is pressed againstthe glass- 32 by a coil spring 288 (Fig. 4) interposed between head 288and bracket 286.

The pulley 205 is rotatably mounted on a frame 206 (Fig. 21) which inturn is mounted on a shaft 280 by means of suitable ears in the frame206 through which passes the shaft 280. The latter has a head 28 lsimilar to head 288, and is slidably mounted in a frame 282 secured toframe !81. A spring 283 (Fig. 2) interposed between head 28! and, theframe 292 normally presses head 28!' It is plain that when the cabinet32 is removed.

the springs 288;283 will push shafts 204, 280 to the left drawingwiththem the ribbon pulleys 203, 205 and causing the ribbon 51 to shift tothe left (Figs. 2, 3, 4, 6 and 11) to bring the red por-- tion over theprinting line.

Secured to a lug 295 formed in frame 292 (Fig. 21) is a bracket 296 onwhich are mounted two pairs of contacts C I, C2 insulated from eachother and bracket 296. Slidably mounted in frame 292 is a rod 29'!(Figs. 1, 2, and 21) to which is secured a cam block 298 of insulatingmaterial adapted to cooperate with buttons 299 of insulating materialsecured to one of each pair of contacts CI, C2. Rod 290 also passesthrough block 298. A spring 300 (Fig. 2), interposed between block 298and the rear part of frame 292 presses block 298 and shaft 291 to theleft (Fig. 2) so that the end of said shaft is kept in contact with theglass 32. Block 298, when the cabinet is in place, has a position to theright of buttons 299 (Fig. 2) but when the cabinet is removed moves tothe left past buttons 299, which it cams to the 'ight (Fig. 1) closingcontacts CI, C2 momentarily, and assumes a position forwardly (to theleft Fig. 2) of said buttons. Thus contacts CI, C2 are closedmomentarily each time the cabinet is removed.

In order to wind the chart 33 on the storage spool 5| and keep the charttaut after it leaves drum 50 there is provided a belt and pulley drivecomprising a pulley 30I secured to spool 5I, a belt 302, and a pulley303 secured to a gear 304 and journalled on a stud carried by frame 35.Gear 304 meshes with pinion I2I and the driving ratios of the pulleys30I, 303 and gears I2 L304 are such that the spool has a tendency tooverwind, slippage between belt 302 and pulleys 30I, 303 permitting suchoperation without danger of tearing the chart.

The various mechanisms and elements of an illustrative embodiment of theinvention having been described in considerable detail, the generaloperation of the invention will now be described with reference to thewiring diagram in Fig. '7 and the fragments of the chart illustrated inFig. 5.

It will be assumed that the operations, both supervisory and automatic,of ten circuit breakers and oil switches are to be recorded and thateach is provided with a control switch like the one illustrated in Figs.9, 18 and 19. The holding contacts of these oil switches and circuitbreakers are designated HI, H2, H9, HIO in Fig. 7 and the correspondingmomentary contacts and interposer magnets will be designated MI, M2, M9,MIO, and IMI, 1M2, IM9,. IMIO. Interposer magnets IMI, 1M2, etc. are inseries with the corresponding holding contacts HI, H2, etc. across linewires W3, W4 leading to a battery B or suitable source of directcurrent.

When any oil switch or circuit breaker is in closed position, itscontrol switch will be in the condition shown in Figs. 9, 18, and 19. Itwill be assumed further that initially all the oil switches and circuitbreakers are in closed condition in a network which is in fulloperation, with the exception that circuit breaker No. I is in opencondition but is about to be closed. Under these circumstances theinterposer magnets of all the circuitbreakers save that of No. I0 willbe deenergized and the interposers left-hand nine interposers (Fig. 1)are over the types 66m corresponding to the vertical columns numbered Ito 9 in Fig. 5. The control switch of circuit breaker No. I0 will haveits momentary contacts MIO in open position and its holding contacts HI0 in closed position so that the interposer associated with interposermagnet IMIO will be over the associated type element 66b which is theextreme right-hand element in Figs. 1 and 6.

The motor ACM is assumed to be in full oper-- ation causing the minuteimpulse contacts MIC to close once each minute immediately after the60th second. Thus type wheel 39 is being stepped forward once eachminute and type wheels 38, 39 together are registering correct time tothe minute. Motor DCM will be inactive under these conditions ascontacts MDI and CC are open.

If now circuit breaker No. In is operated to close its circuit, itscontrol switch holding contacts HIO will open during the first 15 ofcounterclockwise movement of shaft 253 (Fig. 18) deenergizing intcrposermagnet IMIO and permitting its interposcr I to swing to the left overtheextreme right-hand type element 55m (Figs. 1 and 6).

During the remainder of the counterclockwise movement of shaft 253contacts MIO will be closed momentarily. This will establish circuits asfollows: Positive line wire W3, relay RI, and momentary contacts MID, tonegative line wire W4. Another circuit extends from line wire W3,contacts MD3, arrow print solenoid APS, and contacts MIO, to line wireW4. This causes the bent arrow to be immediatley printed on the chart asin the case of the bottom line in Fig. 5. Relay RI closes both itscontacts to energize both starting magnet SM and make and break printingsolenoid MBP. Energization of the starting magnet SM initiates one cycleof operation of the chart feeding mechanism, as described before herein,by disengaging lever I29 from arm I28 and the chart begins to feed atthe prescribed uniform rate of speed. Magnet SM, in deenergizing,operates contacts MDI, MD2, MD3, so that MD3 opens and MDI, MD2, close.The make and break printing solenoid MBP operates as described to forceall the type elements 66m downwardly thus completing the lowest entry inFig. 5. The opening of contacts MIO almost immediately deenergizes relayRI and the solenoid MBP while the opening of contacts MD3 preventsfurther operation of the arrow print solenoid while the chart is beingfed. Closure of contacts MDI (which takes place practicallysimultaneously with release of. lever I 20 from dog I21) causes motorDCM to start.

The chart now begins feeding at a uniform rate of speed and will stopafter one and one-half inches have been fed which will require one fullminute of time. About twenty seconds after the initiation of the chartfeed and the initial entry on the chart (as determined by measuring the'distance between the first and second entries in Fig. 5) circuitbreakers Nos. I, 3, B and I0 are opened whereby the operation of theircontrol switches causes contacts HI, H3, H8 and HI 0 to close energizingthe corresponding interposer magnets which effect shifting of thecorresponding interposers over the related type elements 66b. 7

Next, momentarycontacts MI, M3, M8 and MIO all close momentarily(closure of only one is necessary, however) and this energizes relay RIand solenoid APS as before. Virtually the same events take place as inthe case of the first entry in Fig. 5 but energization of magnet SM hasno effect this time as the lever I21 has already engaged ratchet wheelI20 and has been moved nearly one third of the way around shaft III andthe minute duration contacts have already been operated. Arrow printsolenoid APS cannot be energized as contacts MD3 are now open. Theoperation of solenoid MBP will cause the second entry from the bottom(Fig. 5) to be made. About seven seconds after the second entry, thosecircuit breakers which'were opened and caused the making of the secondentry were reclosed causing a third entry to be made showing that allten circuit breakers and oil switches are now closed.

As the third entry is made at exactly 2.27 P. M., contacts MIC closepractically simultaneously with the operation of the circuit breakersandadditional circuits are established as follows: Line wire W3, contactsMD2, relay R2, and contacts MIC to line wire W4. Line wire W3, timeprinting solenoid TPS, and contacts of relay R2,

to line wire W 3. The operation of solenoid TPS causes the exact time inhours and minutes and the straight'arrow to be printed on the chart, asin the lower left-hand corner in line with the third entry in columns ito id of the fragment of chart in Fig. 5, together with the date.

About five seconds after the third entry, a

fourth entry is caused by the opening of circuit breaker No. 5 and abouttwenty-eight seconds after the fourth entry, near the end of the firstpaper teed cycle, a fifth entry is made when circuit breaker No. 5 isreclosed.

The stopping of the paper feed is caused by the arm I28 (Fig. 14) beingengaged by arm I29 which restores the parts to the position shown inthis figure, disconnecting ratchet I20 from arm 25 and at the same timecontacts MDI, MD! are opened and MD3 reclosed by the engagement of camlug I41 with arm I48, as described before, thus breaking the circuit to,motor DCM which then stops.

It is plain that any desired number of entries can be made during thecourse of a chart feeding cycle and that the exact time to the minute isprinted on each predetermined length of chart to provide a referencepoint by means of which the exact time of the other entries on saidlength of chart may be easily determined by a suitable ruler or scalegraduated in-fortieths of an inch. The bent arrow adjacent the firstentry in columns I to I 0 on each predetermined length of chart providesa means for determining whichtime entry belongs to a group of entries incolumns l to ID indicating changes in the status of the circuitbreakers, as the first time entry above a bent arrow belongs with theentries above and including the one adjacent said arrow, which may becomprised in a strip one and one-half inches wide measured in adirection opposite to the direction of feed. 6.01 P. M. belongs with thetwo entries between .the second and third bent arrows from the bottom ofFig. 5. The time print entries 6.01 P. M. and 6.02 P. M. are exactly oneand one-half inches apart asv they are consecutively made entriesresulting from two successive cycles of chart feed with no interval oftime between.

Thus the time 'entry' minute impulse contacts MIC will thus continue tofunction at one minute intervals to operate magnet TM.

The entry below the highest entry shown in Fig. 5 is one which has beenmade in red ink as a result of removal of the case 32 to insert a newchart. When this is done, the ribbon 51 is shifted as described and atthe same time contacts Cl, C2 are momentarily closed by cam block 298.Circuits are established by these contacts as follows: Line wire W3,time printing solenoid TPS, and contacts CI to line wire W4, thuscausingthe time to be printed to the nearest minute. Wire W3, make andbreak printing solenoid MBP, and contacts C2, to line wire W4 thuscausing the printing of a row of characters from type elements 66m, 661)to'show the status of the circuit breakers and oil switches at the timethe case was removed. The bent arrow is not printed in this case assolenoid, APS is controlled only by actual operation of a circuitbreaker or oil switch. The absence of this bent arrow and the fact thatthe entries at this time are made in red ink indicates the fact that thecase was removed. When the case is replaced contacts Ci, C2 are againoperated and a second entry is made, the highest in Fig. 5, in exactlythe same fashion.

If any changes in the status of the circuit breakers and oil switcheshave occurred while the operator is inserting a new chart, as while useto permit replacement of the chart, but gives an'initial entry to showthe status of the breakers between the time of the changing of the'chartand the first entry resulting from the operation of one or more circuitbreakers.

For instance, if the second red ink entry were absent, a circuit breakermight change its status after the case was removed and before it wasreplaced and a subsequent blue ink entry would show this change but itwould not be distinguishable from the changes which caused the blue ink'entry. Thus a breaker might be open or closed for hours before a changein another breaker would cause anentry to be made on the chart and bothchanges would appear to' have been made at the same time.

" The second red ink entry is obviously a valuable feature as it fillsin a possible gap in the history of operations of the breakers whichgap, if present, might prove serious in many easily imaginablecircumstances-such as demands on the power company for refunds, accidentnegligence suits, and so on.

It is conceivable that two operations of a circuit breaker or otherapparatus connected to the recorder may occur in such close successionthat the entries overlap more or less. This is of no importance as faras the utility of the record is concernedas at least one column willshow nonoverlapping imprints. To illustrate, assume that the third andfourth registrations from thebottom on the right hand half of the chart(Fig. 5) overlapped, in other words, circuit breaker No. 5 reopenedimmediatelyaiter circuit breaker No. l was closed. The M imprints incolumns I to 4, andG to In, would all be repeats and easilydistinguishable since it is impossible for an "M"

